Walls and linings constructed from insulating firebrick are utilized in numerous applications in furnaces, kilns and high temperature applications as primary hot face refractory linings or as insulation behind other refractories. Such walls and linings are typically assembled on-site from smooth sided insulating firebrick and mortar and are laid down in courses.
In industrial furnace and kiln application having walls or linings constructed of insulating firebrick, the furnaces and kilns must be periodically rebuilt. As productivity and profitability are directly impacted by the amount of time taken to rebuild the furnace or kiln, any reduction in the time necessary for a rebuild is desirable.
As an example, insulating firebrick is utilized in the construction of side wall and bottom insulation in carbon anode baking furnaces. Carbon anode baking furnaces are utilized to fire carbon anodes used in the Hall process of smelting aluminum. As 0.4 to 0.5 pounds of anode are consumed in the production of each pound of aluminum, the ability to produce carbon anodes is critical for the production of aluminum. When it becomes necessary for an aluminum smelter to rebuild its carbon anode baking furnace, it must stock pile carbon anodes in order to continue aluminum production during rebuild. Occasionally this is not possible as the carbon anode baking furnace is sized to the needs of the smelter; therefore during a rebuild a smelter must purchase anodes from another source or pause aluminum production.
Attempts have been made in the prior art to supply tongue and groove interlocking insulating firebrick in an attempt to reduce the rebuild time of carbon anode baking furnaces; such attempts have met with limited success as the manufacturing cost of such insulating firebricks is greatly increased. Unlike the tongue and groove in thermally conductive bricks utilized in constructing the flue walls, the tongue and groove in insulating firebricks may not be pressed into the brick's shape during the process of manufacture, but rather must be machined into the fired brick. To machine a tongue into an insulating firebrick is an expensive and time consuming process with the further drawback that the effective height of the insulating firebrick is reduced by the height of the tongue machined into it.
Attempts have also been made in the prior art to provide large prefabricated sidewall insulating modules constructed from insulating firebrick; however difficulties are encountered in aligning and handling such large modules.
Finally, in the prior art, attempts have been made to provide pre-cast modules of tongue and groove design. Such pre-cast modules have been constructed from refractory castable insulating material. Refractory castable insulating material is considerably less durable than insulating firebrick having the same insulating value; as a result, modules constructed from refractory castable insulating material are particularly susceptible to damage in transportation and handling. If a stronger insulating castable is used to produce the modules, the insulating value of the modules is significantly inferior to that of insulating firebrick.
Accordingly, it is an objective of the present invention to provide a method of rapidly assembling durable kiln and furnace linings, and further to provide durable preassembled insulating wall modules, constructed from insulating firebrick, that are self-aligning and interlocking and allow accurate and rapid assembly of side wall insulation.
Other objects and advantages of the present invention will be apparent to those skilled in the art from the following description of the invention.